Lamp socket



I LAMP SOCKET E. w. MCINTYRE Filed July 14, 1923 5 Edward WMeIzzi e Inyernor May 19, 1925.

I Attorneys Patented May 19, 1925.

UNITED STATES PATENT OFFICE.

EDWARD w. mm'rynn, or CLEVELAND, 'onro, ASSIGNOR r HADLEY a. remix,

- or LAKEWOOD, OHIO.

LAM]? SOCKET.

Application filed July 14, 1923. Serial No. 651,556.

To all whom it may concern:

Be it known that I', EDWARD W. Mo- IN'rYnE, a citizen of the United States, residing at Cleveland, in the county of Cuya hoga and State of Ohio, have invented a certain new and useful Improvement in Lamp Sockets, of'which the following is a full, clear, and exact description,- reference being hadto the accompanylng drawings.

Until recently, except for certain types of ornamental, installation of extremely restricted applicability, because of the. low

efficiency of the incandescent lamp com pared to that of the arc lamp and because."

of an inability-to produce reliable incan descent units of suitable size, it has been impractical to utilize incandescent lamps for the general illumination of streets. The development of the gas filled tungsten lamp, however, has provided an;;incandescent lamp having an efficiency comparable with thatof the arc lamp and of a type which can be produced in units of a magnitude equaling or surpassing that in which are la'mps'are customarily produced.

Accordingly,

tungsten lamp has provided an incandescent lamp which is suitable for general street lighting and which has come into widespread use for that purpose.

- In developing units of this'type suitable for street lighting the existing style of lamp base and socket -was retained without I modification as to form. The lamp socket thus retained comprised essentially a base of suitable insulating material, such as porcelain, which carried a shell screwthreadedto engage cooperating screw threads carried by the lamp base and a center contact mounted to engage the center contact of the lamp base. This, socket center contact wasusually resiliently sup-' ported from the socket base in orderto im prove the contact between itself vand the center contact of the lamp base and to im part to the lamp a tendency to move outward whichimproved the contact between the lamp base and the shell.

In lamps of the type described the lamp center socket and produces'an imperfect parently is ef:

tratesat that voltage ofthe the perfection of the gas filled lamp contact and duced a socket base, d'urmg a long continued operation, reaches a relatively high temperature which to ,the adjacent,

contact between the lamp and the socket and particularly between the center contact of the lamp'and the center contact of the socket. In an installation wherein the lamps are arranged in parallel this imperfect contact between the center lamp contact and the center socket contact results only in a slow deterioration ofthe contacts which usually does not destro the socket contact for-an appreciable time but in those installations wherein the lam s are connected in series such an imper ect contact concenpoint a large part of the total series and rapldly destroys the two contacts perhaps throwing the entire series of lamps out of action and in an event necessitatin the renewal of both the lamp and thefisocfiet In addition, the action of the resilient center socket contact, and perhaps of other forces, is efiective in many cases to displace the lamp in the socket durin vibra-' as is tion of the lamp and socket suc caused by the passing of heavy vehicles. I

So far as I am aware, in spite of many attempts, there has been devised heretofore no socket which satisfactorily overcame these difficulties. My invention, however, has produced a socket having a center contact so formed, supported, and connected, as to maintain firm contact with the center a shell so "formed as to retain the lamp ment and accordingly my invention has prowhich avoids the defects existing in sockets theretofore' produced. In the drawingsaccompanying this specification and forming a part thereof I. have shown, for purposes of illustration, one form which my invention may assume. In

these} drawings 4 Figure 1 is an elevation of this illustra tive form of my invention,

Figure 2 is a .plan shown in Figure 1, while Figure 3 is a section on the line 33 of Figure 2.

The socket herein disclosed omits certain parts not essential to the understanding of my invention. This socket, however, prises a socket base 11 which may be of any suitable material such as porcelain and carries, by means of two bolts 12 passing upwardly through the socket base 11, a conducting member 13 provided with a suitable view of the socket comagainst vibratory displaceterminal 14 and overlying the flange 15 of the shell 16 to hold the shell 16 securely .in position upon the socket base 11 and elecof a helical spring 24 coiled thereabout and compressed between the shoulder 25 of the socket base 11 and a washer 26 which encircles the stem 21 below the conductor 20, and limited in its outward movement by means of a head 27 formed at its lower end and arranged to engage an annular shoulder 28 on the socket base 11.

The shell 16 is herein shown as provided with the usual screw threads 17 arranged to engage cooperating screw threads carried by the lamp base and with means to.prevent vibratory displacement of the lamp from the socket which means is herein shown as comprising a wire 29 wound spirally about the exterior of the shell 16, having its ends secured to lugs 30 stamped from the shell 16, and projecting through apertures 31 in the shell 16 into strong frictional engagement with the lamp base and acting thereby to prevent vibratory displacement of the lamp base. It will'be obvious that other means may be employed for this purposebut I prefer to employ the means herein disclosed.

It will be obvious from the above descrip tion that in the construction herein shown the center socket contact is supported independently of the conductor connecting it with its terminal, in a manner which permits the use of a biasing spring independent of the connecting conductor, and in such way that the spring pressureacts to effect movement directly longitudinal of the socket and the lamp and not at an angle thereto as in the sockets now commonly employed, and that the construction herein shown therefore supports the center socket contact in such manner that it maintains constant engagement with the center lamp contact and thus avoids the defects existing in the sockets now generally in use. It will also be obvious from the within description that the construction herein disclosed also provides means to prevent vibratory displacement of the lamp by the spring 24 or otherwise.

The embodiment of m inventionherein disclosed has been deve oped particularly for use for incandescent street 1i hting and is disclosed as so used. It will obvious to those skilled in the art, however, that it may be used otherwise and it will be understood that I contemplate the use of my invention wherever it is applicable. It will also be obvious to those skilled in the art that the particular embodiment of my invention herein disclosed may be variously modified without sacrificing the' advantages or departing from the spirit of my invention and accordingly that thisentire disclosure is illustrative only and that my invention is not limited thereto.

I claim:

1. An electric lamp socket comprising a base having circuit terminals thereon, carrying a screw threaded socket adapted to receive the base of a lamp, provided with a longitudinal aperture therein, and having a center contact structure comprising a stem slidable in said aperture, a head on said stem arranged to engage the center contact of the lamp, spring means acting to force sald head against said center contact-of the lamp,

and a conductor connected to one of said terminals and interposed between said spring means and said head and held by said spring ilneaps in electrical communication with said ieac 2. An electric lamp socket comprising abase provided with a longitudinal aperture, a center contact provided with a depending stem slidable in said a erture, a terminalfor said contact, a con uctor connected to stem slidable in said aperture, a terminal for said contact, a conductor connected to said terminal and surrounding said stem beneath said contact, a washer surrounding said stem beneath said conductor, and a spring acting against said washer to force said conductor against said contact and to tend to move said contact outwardly.

In testimony whereof,I hereunto afiix my signature.

EDWARD W. MCINTYR EQ 

